Originally Posted by El Diablo Rojo
Yes and standing was freak'n scary the first couple of times I tried it! It did give my daughters a good laugh though as they watched daddy fall off his bike several times
I found it's easier if you keep your butt back as opposed to trying to stand over the front wheel.
Speaking of speed on 4" alloy rollers, here's a session I did a while back where I hit 40 MPH:
The rear tire started to slip on the rollers. I actually "lost it" once at 40 MPH, but falling off the rollers at 40 MPH is much better than on the road.
EDIT: My bad... I have the 3" alloy rollers.